Effects of rainfall intensities on soil loss
During the experiment, 12 erosive rainfall events were recorded. Fig. 3 shows scatter plot graphs for the
relationship between Maximum rainfall intensities and soil loss. The best regression equation was selected based on
determination coefficients of the line of best fit.
The relationship between rainfall intensity and soil loss varied across intensities in a systematic way (Fig. 3). For
maximum rainfall intensities in 10 (I10) and 20-min (I20), the dominant equations are in the form of a power function
followed by logarithmic and exponential functions. And for I30, I40 and I50, this relationship tends to be logarithmic.
Detailed analysis of scatterplot graphs (data are not shown), indicates From I25 to I40, a logarithmic equation yields a
determination coefficient higher than power and linear equations, respectively. And from I45 to I55, the equation of
the line of best fit tends to be in the form of a logarithmic equation followed by a linear equation. Finally, the highest
R2 belongs to a linear equation in the I60 and I90 graphs. Only the best equation is shown on each graph.
This result may indicate that in low-intensity events, the effect of storm on soil loss is linear. On the contrary, the
effect of storm intensity on soil loss is non-linear in high-intensity events. Similarly Kandel, Western, Grayson, and
Turral (2004) found a non-linear effect of high intensity storms on runoff and erosion processes. Therefore, it is
possible to conclude that highly intensity and short duration storms lead to greater soil losses. This confirms results